1. Field of the Invention
The present invention relates to a duplex platform system equipped with an information processor which becomes a control system started at the time of running the system and an information processor which becomes a standby system set on standby for starting, and more particularly to a starting control method and an information processor of the system.
2. Description of the Related Art
Conventionally, to prevent a stop of a system caused by a fault of an information processor incorporated in the system, there has been known a duplex platform technology which incorporates a pair of information processors in the system, starts one of them as a control system, and sets the other processor on standby as a standby system to be used instead when the control system fails. The system that uses this technology generally has a configuration shown in FIG. 6. A system 4 (shown) includes devices 1 and 2 which are information processors interconnected to communicate with each other, and a power supply control section 3 which supplies power to these devices.
FIG. 7 shows an operation procedure in the system 4 at the time of starting. In the shown procedure, the device 1 is set as a control system while the device 2 is set as a standby system as an example. When power is supplied from the power supply control section 3 to start running of the system 4, the devices 1 and 2 perform power-on-self-test (POST) operations in synchronization to self-diagnose faults of hardware, thereby determining a success of starting. The devices 1 and 2 wait for completion of each other's POST operation, and execute OS starting operations in synchronization upon completion of both POST operations. Additionally, after waiting for completion of the OS starting operations, the devices 1 and 2 start drivers of peripheral devices in synchronization. Upon an end of the waiting for driver starting, the process proceeds to application operations carried out in synchronization by the devices 1 and 2.
During the execution of the above processing, the devices 1 and 2 use watchdog timers (WDT) for monitoring CPU operations in accordance with periodic updating instructions from CPU's to monitor whether the POST operations, the starting operations and the driver starting are executed normally or not.
An example of a conventional technology that uses the duplex platform technology is described in Patent Document 1 below. According to the technology described in the Patent Document 1, in two synchronously run CPU's of a duplex computer system, a monitoring time of a watchdog timer of a standby side is set longer than that of a control side so that a similar stop of the standby side can be prevented after the control side stops due to a timeout.
Patent Document 1: JP-A-11-175108
However, the conventional system has a problem that it is difficult to shorten a time from the supplying of power to the transfer to the application operations because of the synchronous executions of the operations such as POST operations or OS starting operations between the control system and the standby system. In the case of implementing the conventional system, as each operation needs a waiting step, a general program for causing the CPU to continuously execute a series of starting operations cannot be directly used as a program for starting. In consequence, to introduce the duplex platform technology, work such as changing of the general program or creation of an independent program is necessary regarding starting.